Currency processing devices typically include an input receptacle, a transport mechanism, a sensor, and an output receptacle. As currency bills are transported along a transport path, the sensor senses at least one characteristic associated with the transported currency bills. The currency processing devices typically compare information associated with the sensed characteristic to master data in order to make a judgment about a currency bill. As the number of different types (e.g., denominations, series, etc.) of currency bills increases, the size of the master data set increases. Thus, producing a device that can efficiently process a high number of mixed denomination and mixed series of currency bills is becoming ever more difficult.
However, today, many banknotes have different color prints on each side of the banknote. For example, most United States currency in circulation has two opposing surfaces or sides. One side is generally printed with green ink (e.g., green side) and the other side is generally printed with black ink (e.g., black side). The difference in color can be sensed from an optical sensor and used to determine the currency's face orientation (e.g., face up or face down). Such a determination can be used to increase the speed and efficiency of processing banknotes by reducing the size of the master data set needed for comparison when, for example, denominating a banknote. Additionally, such a determination can be used to decrease the cost of a currency processing device, as the ability to make such a determination reduces the required processing power.